Former PM John Howard dubbed 'war criminal' in Adelaide

Former Prime Minister John Howard has been verbally attacked by a lone protester during a visit to Adelaide tonight.

Mr Howard had just begun his speech at the University of Adelaide when he was interrupted by yelling.

"Mr Howard, you are a war criminal!" the man shouted.

The man continued to yell as he was escorted from Bonython Hall by security while Mr Howard quipped, "ah, it's nice to be back at the uni" which was met with laughter from the audience.

Former foreign minister Alexander Downer accompanied Mr Howard as he delivered his speech titled 'The US and China - is there really a choice?".

The inaugural lecture was in honour of two-time South Australian premier Sir John Downer, the grandfather of Alexander Downer who is a visiting professor at the uni.

Mr Howard rejected the notion that Australia would be forced to choose between the United States and China.

However, he noted it was vital to "understand both our similarities and differences" with the Asian powerhouse, particularly our parliamentary and legal systems.

He reiterated his support of Chinese investment in Australia and expressed disappointment that South Australia had not been more successful in its environmental efforts regarding the Murray Darling Basin debate over the eastern states.